name: Fsutil Zeroing File
id: 4e5e024e-fabb-11eb-8b8f-acde48001122
version: 1
date: '2021-08-11'
author: Teoderick Contreras, Splunk
status: production
type: TTP
description: This search is to detect a suspicious fsutil process to zeroing a target
  file. This technique was seen in lockbit ransomware where it tries to zero out its
  malware path as part of its defense evasion after encrypting the compromised host.
data_source:
- Sysmon Event ID 1
search:
  selection1:
    CommandLine: '*setzerodata*'
    Image|endswith: fsutil.exe
  condition: selection1
how_to_implement: To successfully implement this search, you need to be ingesting
  logs with the process name, parent process, and command-line executions from your
  endpoints. If you are using Sysmon, you must have at least version 6.0.4 of the
  Sysmon TA.
known_false_positives: unknown
references:
- https://app.any.run/tasks/e0ac072d-58c9-4f53-8a3b-3e491c7ac5db/
tags:
  analytic_story:
  - Ransomware
  asset_type: Endpoint
  confidence: 90
  impact: 60
  message: Possible file data deletion on $dest$ using $process$
  mitre_attack_id:
  - T1070
  observable:
  - name: dest
    type: Endpoint
    role:
    - Victim
  product:
  - Splunk Enterprise
  - Splunk Enterprise Security
  - Splunk Cloud
  risk_score: 54
  security_domain: endpoint
tests:
- name: True Positive Test
  attack_data:
  - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1070/fsutil_file_zero/windows-sysmon.log
    source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
    sourcetype: xmlwineventlog